While the disclosure is applicable outside the oil field industry, one such use of the disclosure is in sampling underground reservoir fluids. Sampling of underground fluids is typically beneficial in identifying underground fluid constituents and properties related thereto. For example, fluid sampling may be conducted by deploying a probe having a sampling port to receive formation fluid. The identification of fluid properties is beneficial for understanding the reservoir, planning extraction and production techniques, and even providing information on expected refinement requirements.
A wellbore is generally drilled prior to sampling the underground formation fluids. The probe is limited to providing a single fluid sample at a given depth and radial location of the wellbore. The probe must then be moved to a subsequent location in order to sample fluid at a different depth. The probe is extended from a tool and pressed against the wellbore formation to receive fluid. The fluid may be tested downhole or trapped and later tested at the surface.
Conventional sampling systems, such as the probe, not only receive formation fluid but also unwanted filtrate or contaminates. In many instances, the filtrate or contaminants may be large enough to clog a port of the sampling system. The clogging can prevent any further fluid from being received through the sampling port. Solutions to this have focused on methods to continue sampling rather than any solution related preventing the debris from invading the sampling port. Chief among these techniques is to increase the drawdown pressure at the sampling port with an underground pump. As can be expected, however, such a solution can cause additional dislodgement of particles, preventing further sampling.
Dealing with a clogged sampling port can cause additional rig time, which can be expensive, or even a failure to receive fluid samples, which can lead to inaccurate fluid property measurements, fluid models or other undesirable outcomes that are attempting to be prevented by the sampling operation. Improvements in sampling systems are beneficial in the industry to save expensive rig time and ensure quality formation sample measurements are obtained.